Prevalence and determinants of SHS exposure in public and private areas after the 2010 smoke-free legislation in Greece

The objective of the present survey was to assess the extent and socio-economic determinants of population exposure to secondhand smoke (SHS) in Greece in 2011. The national household survey Hellas Health IV was conducted in October 2011. SHS exposure was based on self-reported exposure within home, workplace and public places. Thirty-three per cent of the respondents reported living in a smoke-free home. Smokers (p < 0.001) and single individuals (p < 0.017) were less likely to prohibit smoking at home. SHS exposure at work, in restaurants and in bars/clubs/cafes was frequently mentioned by 41.6, 84.2 and 90.5%, respectively. SHS exposure in a bar/club/cafe was noted more among single individuals (p = 0.004) and those aged 18-34 years (p = 0.007). Inhabitants of rural areas were more likely to report someone smoking indoors in all the above venues. Public health education and effective enforcement of the nationwide smoke-free legislation are imperative.


Introduction
It is estimated that 40% of children, 33% of male non-smokers and 35% of female non-smokers are exposed to secondhand smoke (SHS). Worldwide, SHS exposure in 2004 is estimated to have caused 603,000 deaths (Öberg et al. 2011), thus classifying as a major contributor to the global burden of disease (Gruer et al. 2012). Exposure to SHS commonly occurs at home, in public areas and in the workplace (King et al. 2012), with legislative actions responsible for reducing exposure to SHS within the latter. Indeed, by the end of 2010, 11% of the world's population was covered by comprehensive smoke-free legislation (Gruer et al. 2012), that have markable public health benefits (Haw & Gruer 2007;Semple et al. 2007;Pell et al. 2008).
Over the past few years, a number of tobacco control policies were implemented in Greece that could have influenced population-based SHS exposure. Between 2009 and 2010, a partial ban of smoking in public places was implemented; while in September 2010, a more comprehensive smoke-free legislation was enacted with the exception of casinos and live music bars with a floor space above 300 m 2 , where separate smoking rooms were still allowed . These legislative actions although identified to reduce SHS exposure in public places were not entirely successful and substantially may have been evaded ). With the above in mind, the aim of this study was to assess the extent and determinants of self-reported exposure to SHS in Greece in 2011 and evaluate the potential role of socio-economic and population differences in SHS exposure.

Sampling methodology
The national household survey Hellas Health IV was conducted in October 2011. The Hellas Health IV survey is an extensive survey that documented lifestyle-related risk factors (smoking, dietary habits, physical activity, obesity, etc.) among the adult Greek population. The designed survey sample consisted of 1008 individuals, aged >18 years old. The survey covered urban areas (2000 or more inhabitants) and rural areas (less than 2000 inhabitants) of the country and each of the 13 geographical regions. Participants were fluent speakers of the Greek language and residents of the above coverage area. The methodology of the previous similar Hellas Health surveys is available elsewhere Filippidis et al. 2012).
Respondents were selected by means of a three stage, proportional to size sampling design. At the first stage, a random sample of building blocks was selected proportionally to size based on the 2001 Population Census of the National Statistical Service of Greece. At the second stage, in each selected area of blocks, the households to be interviewed were randomly selected by means of systematic sampling. Any person or group of persons living in a separate housing unit was considered as a "household" unit. At the third stage, in each household, a sample of individuals aged 18 years old or more was selected by means of simple random sampling. A total number of 1008 effective interviews were completed. Effective response rate reached 45.8%. According to the study design, the sample was representative of the Greek population in terms of age and residence, but the distribution of other demographic characteristics, such as gender and marital status, in the sample is also similar to the general population of the country. Forty-four per cent of the completed questionnaires (n = 443) were back-checked either by phone or by household revisits so as to ensure proper completion. No inconsistency between self-reported and back-checked information on key questions was detected. Interviews were conducted according to the ESOMAR code of practice by trained interviewers. Ethical approval was given by the Ethics Committee of the Medical School of the National and Kapodistrian University of Athens.

Definitions
All individuals were asked to report their gender, age, marital status, level of education and place of residence (urban areas = 2000 or more inhabitants and rural areas = less than 2000 inhabitants). Respondents were classified in three groups according to their educational level (up to elementary school = low, secondary (up to high school) = middle, university, college or technical school = high), age (18-34, 35-54 and more than 54 years of age), marital status (single, married and widowed/divorced) and socio-economic status (high = A/B-C1, middle = C2, low = D/E of the ESOMAR scale) (Filippidis et al. 2012). The ESOMAR scale applied assigns a socio-economic level to an individual, on the basis of the family's main income earner's job category and their level of education.
Participants were also asked if they smoke daily, less than daily or not at all. People who smoked daily or less than daily were characterized as "current smokers". To assess whether participants were exposed to SHS at work, the question "during the past 30 days, did anyone smoke in indoor areas where you work?" was asked. To assess the enforcement of the smoke-free legislation within the worksite the question "which of the below better describes the official policy for smoking indoors at your workplace?" was asked to people who work indoors with the following responses: (1) there is no policy on smoking indoors in my workplace; (2) smoking is completely forbidden indoors in my workplace; (3) smoking is only allowed in designated areas; (4) smoking is allowed in all areas; (5) I do not know/not sure and (6) non-response. Household SHS exposure was assessed with the question "which of the below best describes the rules regarding smoking inside your household?" with the following responses: (1) smoking is prohibited anywhere in my house; (2) smoking is allowed only in specific areas in my house; (3) smoking is allowed everywhere in my house; (4) there is no regulation and (5) non-response. People who chose the first response were considered not to be exposed to SHS at home (no), while the next three answers were considered as positive for household SHS exposure (yes). SHS exposure within public places (bars/ clubs/cafes), was assessed with the question "in the past 30 days, when you were in a bar/club/cafe, how often did you see someone smoking indoors?" Responses of: (1) never; (2) rarely; (3) sometimes; (4) often and (5) always, were provided with responses 2-5 grouped together as a positive response. The same question applied for SHS exposure in a restaurant.

Statistical analysis
Qualitative variables are presented with absolute and relative frequencies, while quantitative variables are presented with mean and standard deviation (SD). For the comparisons of proportions, chi-square tests were used. In order to assess factors associated with SHS at home and work, multiple logistic regression analyses were conducted. The regressions included sex, age, family status, socio-economic level, educational level, residence and smoking status as covariates. For the logistic regression models, we assumed that the contribution of the independent variables in each dependent variable is additive in the logit scale (no product terms were included) and that the relationship between independent variables and the log odds of each dependent variable is constant within categories of each independent variable. Adjusted odds ratios with 95% confidence intervals (CI) were computed from the results of the logistic regression analyses. All p values reported are two-tailed. Statistical significance was set at 0.05 and analyses were conducted using SPSS statistical software (version 13.0).

Results
The Hellas Health IV sample consisted of 1008 participants (484 men and 524 women) with a mean age of 47.2 years (SD = 17.4; range from 18-87 years). Demographic characteristics and smoking-related variables of the Hellas Health IV survey are available online (supplementary Table 1 available via the article webpage). Smoking prevalence was estimated (October 2011) at 38.1% (95% CI: 35.1-41.1), of which 35.6% smoke daily and 2.5% smoke occasionally.
As shown in Table 1, only one-third of the participants stated that smoking is not allowed in their house. Among those who reported being exposed to SHS at home, more than one-third (23.7% of all the respondents) reported that smoking is allowed everywhere within their household. Smoke-free households were reported in a larger percentage among those >54 years (39.5%) followed by 35-54 years old (32.6%) and 18-34 years old (25.6%) (p = 0.001). Moreover, a larger percentage of married (37%) and widowed/divorced (37.4%) respondents reported smoke-free households in comparison to single participants (21.6%).
Regarding the implementation of formal policy on smoking in the workplace, although 50.6% stated that smoking is prohibited in their workplace, 28.8% stated either that there is no official rule or that smoking is allowed in all places and 19.6% stated that smoking is allowed in certain places only. The proportion of participants who reported that smoking is prohibited at all places indoors at their workplace or that smoking is allowed in only certain areas was greater in participants who live in urban areas (52.8 and 21.7%, respectively) than in participants who live in rural areas (44 and 13.2%, respectively, p = 0.025). Τhe proportion of participants who stated that there is no official rule or that smoking is allowed in all places indoors at their workplace was greater in participants who live in rural areas than in participants from urban areas (40.7% vs. 27.7%, p = 0.025). Additionally, smoking indoors within the workplace was reported by 41.6% (95% CI: 36.5-46.7) ( Table 2). Smoking at work was more frequently reported by participants who live in rural vs. urban areas (53.8% vs. 37.4%) and from smokers vs. non-smokers (53.4% vs. 30.2%, p < 0.001) than by participants who live in urban areas.
Smoking in a restaurant during the past 30 days was reported by 84.1% (95% CI: 81.2-87.1) while smoking in a bar/club/cafe was reported by 90.5% (95% CI: 88.3-92.7) of the participants who had visited such establishments during the past month. Again, participants from rural areas (vs. urban) were more likely to report smoking in a restaurant (88.9% vs. 82%) and in a bar/club/cafe (95% vs. 88.7%, respectively). Reporting SHS exposure in a bar/club/café was also associated with marital status and age, as those single and those 18-34 years reported noting smoking in such places at a higher percentage than those married (93% vs. 90%, p = 0.004) or those 35-54 or 54+ (93% vs. 92% vs. 83%, p = 0.004).
In order to assess the factors independently associated with maintaining a smokefree household or workplace, multiple regression analyses were performed, the results of which are depicted in Table 3. Smoke-free households were more likely among married (odd ratio (OR) = 1.91, 95% CI: 1.2-3.04) and widowed/divorced participants (OR = 2.18, 95% CI: 1.15-4.14), compared to those single, while also less likely among smokers (OR = 0.32, 95% CI: 0.23-0.44). On the contrary, gender, age, socioeconomic status, educational level and place of residence were not found to affect the prohibition of smoking in the house in Greece in 2011. Although there was a tendency for more affluent respondents to report a smoke-free household, this did not reach the level of statistical significance. The only independent predictors for SHS exposure in the workplace were place of residence and the respondents' current status of smoking. Specifically, participants who live in rural areas and work in an enclosed place of work had a 2.51 times greater likelihood to report smoking at work compared to participants who live in urban areas. Additionally, smokers had a 2.77 times greater likelihood to report smoking in their workplace, than non-smokers ( p < 0.001). SHS at work was not associated with any other socio-economic or demographic characteristic.

Discussion
Contrary to the decline in the prevalence of active smoking (Filippidis et al. 2012), our study identified significant exposure to SHS at home, in the workplace and in public places, reported almost unanimously by all participants. Previous research using PM2.5 concentrations as an indicator of the implementation of the smoke-free legislation in Greece indicated that while SHS concentrations in hospitality venues decreased by 34% immediately after the 2010 smoke-free legislation, they still remain elevated, with higher concentrations noted within bars and cafes in comparison to restaurants . It is also interesting to note that at the time of the survey, all indoor workplaces were by legislation smoke-free; however, almost one third of respondents who work indoors were not aware of the new legislation.
Smoke-free legislative measures can be highly effective in decreasing SHS exposure and help smokers who want to quit (Fichtenberg & Glantz 2002;Callinan et al. 2010;Thyrian et al. 2010). Overall, smoke-free laws in workplaces may be able to reduce absolute smoking prevalence by 4% (Fichtenberg & Glantz 2002). Indeed, smokers who live in places where total smoking bans are in force for bars, restaurants and their work-site are more likely to support these policies (Borland, Yong, Siahpush, et al.  2006; Hyland et al. 2009) and the level of support increases the longer the policies are in effect (Brooks & Mucci 2001). Our findings indicate that the implementation of the smoke-free legislation in Greece may not have been as successful as those implemented within other European nations, such as Italy, where the implementation of a comprehensive smoke-free legislation led to a substantially decreased SHS exposure (10.2% in public places and 15.6% at home) or Ireland and France which almost completely eliminated smoking in bars (from 97 to 3% and from 84 to 3%, respectively) (Martinez-Sanchez et al. 2012). Considering the fact that the level of smoking permissiveness is correlated with the proportion of smokers in a given country (European Commission 2010) and the fact that a higher number of smokers can also influence the observed higher exposure to SHS (Martinez-Sanchez et al. 2012), in Greece a significant level of SHS exposure in public places would be expected. This would apply mainly for urban areas, as their inhabitants are more likely to be current smokers (Pitsavos et al. 2003;Idris et al. 2007). However, while our results are consistent with this hypothesis that SHS exposure is correlated with the prevalence of smoking, we identified that rural and not urban populations reported to a greater extent SHS exposure in the workplace and in public areas. It is possible that the above may be attributable to (1) the lack of adequate structures for monitoring compliance and imposing penalties in rural areas and (2) differences in employer characteristics between rural and urban areas. It is possible that larger industries and multinational companies, which apply more strict internal rules (including smoke-free legislation), may be more likely to be established in urban hubs; however, further research is needed so as to identify the characteristics of the workplaces that permit smoking in their premises despite the existence of a relative legislation (Lazuras et al. 2012).
Previous research in Greece and other countries indicated that non-compliance with smoking restrictions may be mediated by factors such as personal smoking status (Ravara et al. 2013), tobacco dependence, anticipated regret from tobacco-related health damage, existence of smoke-free households, perceived prevalence and social acceptability of smoking (Borland, Yong, Siahpush, et al. 2006;Lazuras et al. 2009;Vardavas et al. 2011). Moreover, the fact that the SHS exposure in a bar/club/cafe was also associated with marital status and age is expected and consistent with literature which documents that younger age groups are the most exposed to SHS (Jarvis et al. 2001;Ellis et al. 2009). Within the current nationwide survey, only marital status and current smoking status had an effect on the likelihood of household SHS exposure.
Smoke-free households were more likely to be found among those who were married compared to those living as single people. This finding is in line with the published literature (Borland et al. 1999;Gilpin et al. 1999;Borland, Yong, Cummings, et al. 2006) which noted that smoking may be regulated more tightly in households were children are present, and in this study marital status may act as a proxy for parity (Twose et al. 2007). Our results indicate that only one in three households in Greece are smoke-free, a fact that has been noted in other studies in Greece among parents with small children (Vardavas et al. 2006;Vardavas et al. 2010) and thus may pose as a significant source of SHS exposure. This household exposure to SHS may have a detrimental impact on child health and development as it has been associated with numerous adverse outcomes such as upper and lower respiratory infections, asthma, wheezing (Jones et al. 2011;Öberg et al. 2011;Burke et al. 2012), invasive meningococcal disease (Murray et al. 2012), leukemia, lymphoma and brain tumors in children (IARC Working Group on the Evaluation of Carcinogenic Risks to Humans 2004). The importance of regulating SHS exposure at home is not only limited to the direct health gain, but also may have a societal impact, as having a smoke-free household has been previously associated with active compliance to smoke-free legislations, even among smokers (Borland, Yong, Cummings, et al. 2006;Vardavas et al. 2011).

Strengths and limitations
Hellas Health IV is a repeated nationwide study that leads to generalizable conclusions regarding the characteristics of the smoking epidemic, since the sample size is adequate and the survey has a sound sampling methodology. However, although our study relies on an adequate sample size from which we can extrapolate the results to the general population, it is possible that specific analyses in subgroups may not be generalizable, due to their moderate sample size. Moreover, response rate was not very high; a fact which could negatively affect the representativeness of the sample. Low response rate could be attributed to the fact that the respondents should be available at the time of the survey and dedicate time (almost 30 min) in order to take part to an extensive survey such as Hellas Health IV and respond to 111 questions. Responses remain prone to response bias as they were self-reported, with active and passive smoking not biochemically assessed.

Conclusions
In Greece, despite the comprehensive smoke-free legislation in force, significant exposure to SHS is documented in public places such as restaurants and bars/clubs/ cafes as well as in private settings such as worksites and home. Article 8 of the Framework Convention on Tobacco Control (FCTC) calls for the adoption of smokefree legislations and for the need to reduce exposure to SHS (Bovet et al. 2012). As Greece has ratified the FCTC in 2005, action should take place to protect the population from SHS exposure in public and private places. While the regulation of SHS exposure in public places is possible, should strict enforcement take place, the regulation of household SHS exposure may be feasible through educational interventions, via the mass media or schools. With the above in mind, our study results highlight the need for health promotion programmes and the implementation of a strict comprehensive nationwide tobacco control policy in Greece, especially in rural areas and among the younger segment of the population. Finally, along with the establishment of adequate structures for monitoring compliance with legislative measures and imposing penalties, adherence and active protection of legislation could, therefore, be achieved.